DigitalOcean.com starts at $5/mo for a VPS that is going to be faster and better than most shared hosts would be. Of course you can scale it up and down as needed. Their $10 a month server is actually really powerful for any sites that get less than say 10,000 visits a day. They even have one-click wordpress installs now among many other open source programs.
I use DigitalOcean now for almost all of my sites. I have abandoned wordpress lately and so I am using custom built sites for all my projects. DigitalOcean is awesome.